@Yves-Jenni
This morning again: I selected walking mode, but as soon as I start the activity, the display goes dark and there’s no way to turn it back on. Right now, I’m still, I’ve finished my walk, but the watch is practically dead.
As with previous times, the activity in question was carried out on the beach, so I don’t know if the issue could be related to some sort of display protection. For completeness, I should point out that the display brightness is set to “high.”